Photographic gelatin layer containing a condensation product of an ethylol cyanamidewith a fatty acid



Patented July 11, 1944 PHOTOGRAPHIC GELATIN LAYER CONTAIN ING A CONDENSATION PRODUCT OF AN ETHYLOL CYANAMIDE VVITH A FATTY ACID Donald R. Swan and Carl G. Lindqulst, Rochester, N Y., assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing.

6 Claims.

This invention relates to photographic light-- sensitive materials, such as sensitized film, plates, and paper, comprising layers in which sensitive silver salts are suspended or dispersed in gelatin or other suitable vehicle, and optionally comprising other layers as well. More particularly, it relates to the use of certain agents to facilitate the spreading of gelatino-silverhalide layers and, in fact, the spreading of any gelatin or other hydrophilic colloid layers which are deposited from a predominantly aqueous medium and used in such photographic mate-.

rials.

. Our invention perhaps finds its greatest usefulness in the manufacture of photographic film in which a sensitive gelatin emulsion layer is applied to the film base, set by chilling, and then, without drying, is overcoated with a protective gelatin layer, the sensitive gelatin emulsion layer containing such a spreading agent. The general process of coating film base with a sensitive gelatin emulsion layer, setting by Application September 25, 1941, Serial No. 412,282

chilling, and overcoating with a protective gelatin layer, is fully set forth in U. S. Patent No. 1,699,349 of William B. Dailey.

If a sensitive gelatino-silver-halide emulsion is coated on a filmbase (which has usually first been coated with a thin layer or substratum of gelatin or other colloid and dried) without the addition of a suitable spreading agent, difliculty is experienced in that the emulsion will spread unevenly. Moreover, if the emulsion, while still in a wet, chilled condition, is overcoated with a protective gelatin only acts as a spreading agent for gelatin, but

by some mechanism not clearly understood, it prevents the formation of air bubbles between the gelatin layers when a wet, chilled gelatin emulsion layer containing the proper concentration of saponin is overcoated with a warm gelatin solution.

However, saponin, being a naturally occurring material of vegetable origin, is of varying quality, and synthetic agents are to be preferred because of their more constant and controlled properties. Because of its varying quality,

some batches of saponin may cause an increase in fog or a decrease in sensitivity in the sensitive emulsion, and in some cases may produce little or no improvement in spreading. This is true whether the saponin be employed in the emulsion layer or in the protective overcoating or other layer.

Other surface-active materials have been tried in place of saponin, but many of them, while they may act to some extent as spreading agents for gelatin, have been found to be entirely ineffective for preventing the-formation of air bubbles when a wet, chilled gelatin emulsion containing them is overcoated with a warm gelatin solution, and many of them are objectionable from the standpoint of fogging or desensitizing the emulsion.

We have found a class of surface-active comlayers which are deposited from a predominantly aqueous medium and used in photographic films, plates, and paper, but which, when incorporated in layers such as sensitive gelatin emulsions, are superior to saponin in the prevention of bubble formation when the wet, chilled emulsion layer is overcoated with a warm gelatin solution or other hydrophilic colloid of the type which is deposited from a predominantly aqueous medium. These compounds are the condensation products of an acid selected from the group consisting of the aliphatic monobasic carboxvlic acids of from '8 to .17 carbon atoms and the alicyclic acids, with an ethylol cyanamide. The ethylol cyanamides and their preparation are described in U. S. Patent No. 2,244,421 of Walter P. Ericka; Their condensation products with the acids defined, for example, lauri'c, myristic,

pelargonic, lauroxyacetic, naphthenic, abietic or hydroabietic acid may be prepared by heating the acid with the ethylol cyanamide on the steam bath. For example, 2 moles of the monoethylol cyanamide whose preparation is described in Example I of U. S. Patent 2,244,421 is heated with 1 mole of lauric acid on the steam bath for one hour, to give a condensation product which is of great value for the purposes of our invention.

Any of these ethylol cyanamide condensation products may be incorporated in the sensitive gelatin emulsion at any point in its manufacture such that they will be present during its coating, in the proportion of from 0.005 to 0.1 part of condensation: product" per..100. parts by weight of wet emulsion. This gives a condensation product content of 0.05% to 1.0% in the dried emulsion layer. They have no detrimental effect upon the photographic properties of the emulsion, but, on the contrary, improve them. It is believed that the property of the spreading agent which prevents the formation of air bubbles when a wet, chilled gelatin emulsion is overcoated with a warm gelatin solution, also tends to prevent the formation of air bubbles, repellent spots, etc., on the surface of a sensitive emulsion containing such a spreading agent, when that emulsion, coated on a film, plate, paper, etc., is immersed in a developer.

As above pointed out, the ethylol cyanamide condensation products defined may b used in any one or more of the colloid layers used to build up a photographic sensitive element upon a'base such as film, glass, paper, etc., which layers consist of gelatin or other hydrophilic colloid which is deposited from a predominantly aqueous medium, i. e., a medium used as the solvent for such materials in which water predominates, the remainder of the medium contributing to give a good dispersion of the colloid. If two superposed colloid layers are present, either, neither or both of which may be photographically sensitive, the spreading agent may be used in either layer or in both layers. However, where a wet, chilled light-sensitive gelatin or similar layer is to be overcoated with a warm solution or emulsion of gelatin or similar material, the presence of the spreading agent in the wet, chilled layer is essential for preventing the formation of air bubbles between the layers. When these ethylol cyanamide condensation products are incorporated in the overcoat, they produce, on drying, a slightly roughened surface similar to th orange peel effect sometimes observed in lacquers. This is a highly desirable effect in photographic film, since such a surface tends to minimize the production of static markings when the film is handled under dry conditions. Such a surface also supplies tooth, which aids in retouching.

Examples of hydrophilic colloids other than gelatin, which are useful as layers in photographic it may be desirable to coat them at different temperatures.

In the claims appended hereto, where a "hydrophilic colloid depositable from a predominantly aqueous medium is referred to, it will be understood to mean any hydrophilic colloid which can be deposited from a medium which is predominantly aqueous, the remainder of the medium being an organic solvent which contributes to the dispersibility of the colloid; examples of such organic solvents for this purpose are acetone, ethyl alcohol, ethylene glycol, monoacetin and pyridine.

What we claim as our invention and desire to be secured by Letters Patent of the United States is:

1. Photographic sensitive material comprising a layer of a hydrophilic colloid depositable from a predominantly aqueous medium, said layer containing from 0.05% to 1.0% of a condensation product of an acid selected from the group con-- sisting of the aliphatic monobasic carboxylic acids of from 8 to 1'7 carbon atoms and the alicyclic acids, with an ethylol cyanamide.

2. Photographic sensitive material comprising a gelatin layer containing from 0.05% to 1.0% of a condensation product of an acid selected from the group consisting of the aliphatic monobasic carboxylic acids of from 8 to 17 carbon atoms and the alicyclic acids, with an ethylol cyanamide. 3. Photographic sensitive material comprising a base and two superposed gelatin layers, in which the gelatin layer nearer the base contains from 0.05% to 1.0% of a condensation product of an acid selected from the group consisting of the aliphatic monobasic carboxylic acids of from 8 to 17 carbon atoms and the alicyclic acids, with an ethylol cyanamide.

4. Photographic sensitive material comprising a base, a photo-sensitive gelatin emulsion layer and a gelatin overcoating on the emulsion, in which the photo-sensitiv gelatin emulsion layer contains from 0.05% to 1.0% of a condensation product of an acid selected from the group consisting of the aliphatic monobasic carboxylic acids of from 8 to 1'7 carbon atoms and the allfilms, plates, paper, etc., are the water-soluble cellulose derivatives such as well hydrolyzed cellulose acetate (described in U. S. Patent No. 2,110,-

491 of Salo) and cellulose esters of hydroxy monocarboxylic acids, such as lactic or glycollic, and salts of cellulose esters of dicarboxylic acids, such as phthalic (described in U. S. Patent No. 2,127,573 of Sheppard and U. S. Patent No. 2,127,- 621 of Staud), as well as polyvinyl alcohol and hydrolyzed'polyvinyl acetate (described in an application of Wesley G. Lowe, Serial No. 318,559,

filed February 12, 1940, now U. S. Patent No.

2,286,215) and water-soluble polyvinyl acetals (described in U. S. Patent No. 2,211,323 of Fordyce) When colloids other than gelatin are used,

cyclic acids, with an ethylol cyanamide.

5. Photographic sensitive material comprising a base, a photo-sensitive gelatin emulsion layer and a gelatin overcoating on the emulsion, in which the overcoating contains from 0.05% to 1.0% of a condensation product of an acid selected from the group consisting of th aliphatic monobasic carboxylic acids of from 8 to 17 carbon 7 atoms and the alicyclic acids, with an ethylol cyanamide.

6. Photographic sensitive material comprising a gelatin layer containing from 0.05%: 1.0% of a condensation product of an ethylol cyanamide with lauric acid.

DONALD R. SWAN. CARL G. LINDQUIBT. 

